Patent GB-975287-A (GB)
Title: Improvements in metering valve assemblies for use with pressurized containers
IPC: B65D83/14
Filed: 1962-06-08
Abstract: 975,287. Delivering measured quantities of liquid. SEARY Ltd. June 8, 1962 [June 8, 1961; Sept. 27, 1961], No. 22316/62. Heading B8N. [Also in Division F1] A metering valve assembly 1 for use with a pressurized container utilizing a non-soluble gaseous propellant, such as a nitrogen or nitrous oxide, and adapted to sealingly engage the hollow depressible valve stem 6 of a dispensing valve 3 comprises a body portion 2 having a measuring chamber 27 in communication with the interior of the hollow valve stem when the stem is depressed, a discharge passage 22 in the body portion connecting with the chamber, a movable wall 24 forming a wall of the chamber, resilient means 25 for moving the wall, and closure means 33 for closing off the discharge passage from the chamber operable by depression of the cap. The wall 24 is in the form of a plunger sealed with the cap by means of a diaphragm 26 and normally urged downwardly into contact with the lower part of the body by means of a spring 25. The closure means is in the form of a flexible sleeve 33 constructed as an integral part of the body which may be of moulded polyethylene. In operation, as shown in Fig. 2, when the cap is depressed, the sleeve 33 is urged into contact with a tapered member 30 so that the sleeve closes the outlet 22, continued movement of the cap then causing the valve spindle 6 to be moved so that a port 10 is moved out of contact with a sealing washer 9 in the container, liquid in the latter then being forced by a pressurized gas, through the hollow stem thereby forcing the plunger upwardly until the chamber is filled; an adjustment screw may be provided in the cap so as to abut the plunger and vary the capacity of the chamber. Upon release of the finger pressure on the cap, the spindle 6 is urged upwardly by a spring 8 until the port 10 is closed and the sleeve 33 is moved out of contact with the discharge passage 22 by means of a resilient member 34. The liquid is now forced out of the chamber by the spring-loaded plunger 24. In the modification shown in Fig. 5, a body 51 is provided with a tubular portion 55 for connecting the cap to the end of the stem 6 and for guiding a piston 53 loaded by a spring 54. The discharge passage is opened or closed by means of a resilient member 56 secured to a button member 57 mounted on the body; alternatively, a closure member may be formed on the button and arranged to open or close the bore in the tubular member 55 (Fig. 6, not shown). In the further modification shown in Fig. 7, the valve arrangement for controlling the discharge passage 110 is formed with interengaging tapered portions 104, 105, the portion 105 being formed in a ring 106 having a passage 111 and the portion 104 on a resilient diaphragm 103 secured to the body 101. In the construction shown in Fig. 10, the measuring chamber is formed by an expansible sac 142<SP>1</SP> such that when the valve stem is depressed as shown, pressurized liquid flows into the hollow stem to thereby expand the sac, the liquid being prevented from escaping to atmosphere by means of a closure member 147. Upon release of pressure on the stem, the closure member is opened and the resilience of the walls of the sac forces the liquid through the outlet 149. In a still further modification, the measuring chamber, including a spring-loaded piston, is mounted within the container, the hollow valve stem being fitted on its outer end with a nozzle.